Mast drilling machines are utilized in surface mining operations where the mast drilling machine drills bores in rocks and other materials in desired locations. The mast is movably coupled to a vehicle such as a truck for transportation. In operation, a lift system moves the mast from the transport position to an operation or drilling position. When in a drilling position the vehicle functions as a counterweight or base for the mast to prevent the mast from tipping over, causing significant damage and danger.
The lift system rotates the mast about a pivot axis from the transport position to the drilling position. The drilling position can occur when the mast is perpendicular (at 90°) to the ground. Alternatively, during operation, drilling is desired at an angle, not only at angles less than 90° degrees, where the machine is disposed between the mast and the ground, but also at angles past 90° degrees such as up to 105° degrees when the mast is angled away from the vehicle. Specifically, linkage is proved to hold the mast in such position without tipping as a result of vibrations during the drilling process.
Japanese Patent Publication No. 4880642B2 provides a vehicle mounted mast device with framework supporting the device on the vehicle. Linkage, including a hydraulic system is utilized to support the mast and move the mast into desired locations. Still, hydraulic systems can be complicated, expensive to manufacture, and prone to fatigue and wear. Specifically, the hydraulic device or cylinder responsible for supporting and rotating the mast is subject to significant forces resulting in wear, fatigue, strain, malfunction, and the like.